1) Technical Field of the Invention
The present invention relates to a data communication apparatus in a data communication system, a data communication process, and a computer program, which are used for safely controlling and maintaining the household and security appliances in a house via networks.
2) Description of Related Arts
Infrastructures of communication network systems have remarkably been developed in these days. Several techniques are already available for remote control and monitor of electrical household and security appliances, e.g., the status and operation thereof, with use of the communication apparatus secured in the house and the external device such as a mobile phone. The electrical household appliances include a washing machine, an air-conditioner, a refrigerator, and a boiler, and security appliances include an open/close sensor and an obstacle detecting sensor equipped with a door and/or a window.
While the advantage of remote control and monitor in the network system can be fully enjoyed, there are increased risk of improper and/or illegal access to the household and security appliances, thereby allowing the unauthorized third party to control thereof irrespective of the users' intention. In particular, the abuse of the household appliances generating a substantial amount of heat and water could cause a devastating problem. Also, the security appliances includes, in general, operation modes having a stay-in and go-out modes for selecting a security level, and a cancellation mode for canceling any operation modes of the security appliances. If the security appliance is illegally accessed from the outside so as to intentionally cancel all operation modes, then such security appliances would be useless.
However, if the access to the appliances from the outside of the house is totally prohibited, the advantage for use of the communication apparatus in the network system allowing the remote control and monitor of the household and security appliances would substantially be sacrificed. Therefore, the advantage of the communication apparatus has to compromise with the security risk by the illegal access.
Meanwhile, one of the conventional communication configurations having a specific charge system, e.g., charging 10 yen per minute, includes an analog telephone network providing communication service for telephone subscribers. In this communication configuration, the user has to make a call so as to communicate with the communication apparatus. Thus, since the connection of the communication configuration is made only when necessary, the high level of the security is maintained although the communication speed is low. The Internet protocol telephone that has recently been developed may also be categorized within this type of the communication configurations. On the other hand, another type of communication configurations having a non-specific charge system, e.g., charging 2000 yen per month irrespective of connection time, includes a non-specific high speed digital network such as the ADSL (Asymmetric Digital Subscriber Line) Internet network, which has a great communication speed. However, a continuous communication of this type of networks could expose the appliances to the risk of illegal access from the outside. As highly expected in near future, the household appliances will be accessed from the outside via the high speed digital communication network such as the ADSL network for remote control thereof. Therefore, the security against the illegal access should be warranted.
Thus, taking into consideration of the aforementioned drawbacks, the present invention has a purpose to provide a communication apparatus preventing an improper access to the appliances and allowing one or more particular persons to access the appliances under a particular condition.
Also, the present invention has a purpose to provide the communication apparatus preventing the improper access by informing when the access is available. The present invention may be adapted to various network systems.
It should be noted that the “high speed” digital communication network has the transmission speed greater than several hundred kilo bps including a fiber optical and cable networks.